1. Field of the Invention
The present invention relates to an attachment device and, more particularly, to a sucker for attaching an article to an attached face, such as a wall, plane and the like.
2. Description of the Related Art
A conventional sucker in accordance with the prior art shown in FIG. 1 comprises a sucker body 10 and an air extraction mechanism 12 connected with the sucker body 10. The sucker body 10 has a side provided with an attachment portion 11 which has a periphery provided with an annular flange 111. The attachment portion 11 of the sucker body 10 has a surface provided with a plurality of slits 112 with circular or cruciform shape. The attachment portion 11 of the sucker body 10 has an interior provided with an air channel 113 connected between the slits 112 and the air extraction mechanism 12. In operation, when the flange 111 of the sucker body 10 abuts an attached face, the air extraction mechanism 12 is pressed successively to extract the air in the attachment portion 11 of the sucker body 10 outward so that the air in the attachment portion 11 of the sucker body 10 is introduced through the slits 112 and the air channel 113 and is drained outward from the air extraction mechanism 12, and the attachment portion 11 of the sucker body 10 is evacuated. Thus, the slits 112 of the attachment portion 11 of the sucker body 10 form a negative pressure or vacuum state so that the central portion of the sucker body 10 is attached to the attached face. However, when the attached face is uneven or unsmooth, the sucker body 10 cannot be attached to the attached face closely and tightly, so that the sucker body 10 is easily detached from the attached face during a long-term utilization. In addition, the contact area of the slits 112 of the sucker body 10 and the attached face is not large enough so that air will exist in the attachment portion 11 of the sucker body 10 after evacuation of the attachment portion 11 of the sucker body 10. Thus, the suction force of the sucker body 10 is reduced during a period of time so that the sucker body 10 is easily detached from the attached face.